Coupling system for interchangeably



EXAMINER Dec. 25, 1956 A. E. HUNT Re. 24,259

COUPLING SYSTEM FOR INTERCHANGEABLY CONNECTING THE WIRING SYSTEMS OFTRUCKS AND TRAILERS Original Filed March 6, 1952 2 Sheets-Sheet 1 Fig.3

Arthur E. Hunt INVENTOR.

Dec. 25, 1956 A. E. HUNT Re. 24,259

COUPLING SYSTEM FOR INTERCHANGEABLY CONNECTING THE] WIRING SYSTEMS OFTRUCKS AND TRAILERS Original Filed March 6, 1952 2 Sheets-Sheet 2 Fig.5

Arthur E. Hunt IN VEN TOR.

BY @waoiia (puny E United States Patent COUPLING SYSTEM FORINTERCHANGEABLY CONNECTING THE WIRING SYSTEMS 0F TRUCKS AND TRAILERSArthur E. Hunt, Rensselaer, N. Y., assignor to Arthur E. Hunt, George B.Beatty, and Maurice W. Grady as tenants-in-common Original No.2,660,679, dated November 24, 1953, Serial No. 275,201, March 6, 1952.Application for reissue November 17, 1955, Serial No. 547,593

9 Claims. (Cl. 307-10) Matter enclosed in heavy brackets [II appears inthe original patent but forms no part of this reissue specification;matter printed in italics indicates the additions made by reissue.

This invention relates to the electrical coupling between the wiringsystems of tractors and trailers or of tractortrailer combinations and,in general, to the making of electrical connections between loadhandling vehicles, and it has for its object to provide a connector orcoupling system which may be used for coupling ditferent types oftractors with difierent types of trailers, each provided with a wiringsystem of its own, for operating its direction signals, stop signals,position lights, etc., and which permits to use a simple and safestandard coupling means between the cables of the said vehicles to becoupled notwithstanding the fact that the vehicles are equipped withwiring systems which may considerably diifer from each other.

The background of this invention will be better understood if it ismentioned that each trailer has a number of signal and position or bodylight circuits, many of them prescribed by the State laws, which must beoperated and controlled by the driver on the tractor with which thetrailer happens to be coupled. As some of the controls have to beexercised individually to operate each of the signals in conformity withconditions on the road, such signals being, for instance, thedirectional signals or the stop signals, while other circuits have to becontrolled collectively, an example being the groups of position lightsor body lights carried by the vehicles, a multiwire cable with a numberof independent conductors is provided, the number of conductors being[squal] equal to the number of types of signals or groups of lights usedon the vehicles. Usually the number of control circuits is either fouror six, although this number may be smaller or larger.

As has been mentioned the wiring systems in practical use difl'er fromeach other and many carriers use their own wiring system merely joiningthe wires or leads to a coupling member such as a member of a plug andsocket connection into which the corresponding connector member of thetractor has to be inserted.

This system of wiring is clearly only suitable for fixed combinations oftractors and trailers, whether the trailer is a complete separatevehicle or merely is a semitrailer. Such wiring systems, however, becomeunworkable if tractors and trailers of diflerent origin and differentmakes have to be coupled with each other.

However, it is a rule, especially with larger shipping and haulingorganizations, that different types of tractors and trailers have to becoupled, sometimes because each tractor has to make many runs before atrailer is unloaded and ready for further hauling so that the tractorcannot operate within a fixed combination, while on the other hand,organizations do not use exclusively vehicles made by a singlemanufacturer; partly such difierent combinations also result from thefact that the trailers are provided by the customers or by organizationswhich are difierent from those providing the tractors. In fact it is therule that during a single twenty-four hour period a tractor has to haulquite a number of trailers each of a diiferent type.

A further difiiculty when connecting the tractor and the trailer stemsfrom the fact that some tractor and trailer systems are only equippedwith a four wire system while others are arranged with a six-wireconnection. Therefore, a direct connection between the connecting meansof the tractor and trailer is not possible.

On account of these dilferences of the electric wiring systems and ofthe wiring carried by both vehicles each combination of trailer andtractor in which vehicles of difierent types are coupled entails certainrepair work in the nature of rewiring. This type of work is not only aconstant burden for the personnel, but is also a source of unsafety,because sometimes some connections match and therefore lead to theerroneous belief that the connections have been matched with the resultthat a dangerous confusion between signals may result.

The invention therefore has for its main object to provide a couplingsystem in which a fixed plug connector associated with the trailer andwith the tractor may be used but in which the tractor embodies, betweenthe switch or distributing box and the plug connection, a connectionshifting device which permits to change the connections between thetractor controls and the pins or other connecting elements of the plugconnection.

A further object of the invention consists in providing the tractor notonly with a connection shifting means but also with a dual plugconnector having dilferent connector faces each adapted for connectionwith a ditierent number of wires and elements.

A further object of the invention consists in providing, on a tractorbetween the plug connection with which the trailer is connected and thedistributing box of the tractor, a switch bank with individuallyadjustable switches, each having a number of contacts equal to thenumber of lines to be connected with the trailer and each capable ofconnecting any control circuit of the tractor with any one of theconductors leading to the plug connection of the tractor.

A further object of the invention consists in providing a tractor plugconnection with a number of individually movable and insertible jackswhich, after insertion, may be held in their position and may beprotected by a holding cap.

Further objects of the invention will be apparent from the followingdetailed specification.

The invention is illustrated in the accompanying drawing showing severalembodiments thereof. It is however to be understood that the embodimentsof the invention which have been illustrated are shown by way of exampleonly in order to explain the principle of the invention and the bestmode of applying said principle. The specification and drawing will notgive a complete survey of all possible embodiments of the invention anda departure from the modifications illustrated is therefore notnecessarily a departure from the principle of the invention.

In the drawing:

Figure 1 illustrates a tractor-trailer combination with electricalconnections made by cables ending in a plug connector.

Figure 2 illustrates diagrammatically this combination showing thevarious circuits of the tractor and of the trailer and their connectionby means of a plug connector.

Figure 3 shows a perspective view of one modification of the inventionwith two members of the plug connector removed from each other and readyfor being connected.

Figure 4 is a diagram of the connections illustrating the wiring systemof a tractor with a dual plug connector and with a connection shiftingmeans inserted between the cable leading to the distributor box and thedual connector, the example shown being one in which the tractor isequipped with a six wire system.

Figure 5 is a similar diagram illustrating the case of a tractor whichis equipped with a tour wire system.

Figure 6 is an elevational view of the dual plug.

Referring to Figure l the general arrangement of a tractor-trailercombination is shown in this figure in which a semi-trailer 10 and atractor 11 are connected by means of multi-wire cables 12, 14 and a plugconnector 15.

As seen in Figure 2 in which a six wire connection is diagrammaticallyillustrated, the tractor 11 which carries the grounded battery 27 isprovided with a distributor and switch box 34 to which, in addition tothe operative circuits of the tractor, such as the ignition circuit, theheadlights and other circuits, the body lights 25, the signals 26indicating directions and the stop light 36 are wired. It will beunderstood that the direction signal, the stop signal, the cautionsignal, if any, and the body and position lights of the trailer must becontrolled by the controls which are provided in the tractor for thecorresponding signals. Therefore each direction signal 30, the stoplight 31, the caution or emergency light 32 and the lateral positionlights 29 as well as the body lights 28 are energized each by a separatewire which leads to the plug connector socket member 33 of the trailer,the wiring system varying according to the system selected by themanufacturer of the trailer. Further, some trailers are only providedwith a wiring system including four wires leading to a separate circuitfor each direction signal, a circuit for the automatic stop light, and afurther circuit connected with all other circuits which need not bespecially controlled in accordance with conditions on the road.

In order to be able to control all the trailer circuits by the controlsprovided on the tractor for the corresponding circuits the tractor isprovided with a plug member 35 coupled with the trailer plug member 33in such. a way that the corresponding tractor and trailer circuits areconnected. As above described, a special connection shifting means ishowever necessary to cope with the difliculty of connecting the twosystems notwithstanding their dilferent systems of wiring. The mostsimple interchangeable connection between the tractor and the trailerwhich needs, however, individual attention for making the properconnections is illustrated in Figure 3. In the example shown in thisfigure the trailer and the tractor have the same number of wires. Thetrailer 10 is provided with a plug member 16 which may be provided withbayonet pins 17. The member 16 contains the sockets 18 each of which isconnected with one of the wires of the cable indicated at 22.

The tractor has a plug member, generally indicated at 19, [comprises]comprising a series of individual jacks 20 with which the wire strandsof the cable 21 of the tractor are connected. Each Wire with itsinsulation projects from the cable 21 to a certain extent and isprovided with an individual jack 20. A cap 23 with bayonet slots 24 isslidably mounted on the end of the cable 21 and when the connectionshave been made by inserting the jacks 20 into the sockets 18 the cap ismoved towards the member 16 and is fixed on said member by means of thebayonet slots.

The connection between the wires of the tractor and the correspondingwires of the trailer must in this case be made individually. It ispreferable to mark the jacks 20 and the sockets 18 of the member 16 withcolors or by impressed characters or the like, so that the connectionsmay be made in accordance with these characters.

An improved system requiring less individual attention to details of theconnection but which nevertheless [proviles] provides freelyinterchangeable connections is shown in Figures 4 and 5.

Figure 4 diagrammatically illustrates the connection of a tractor thewiring system of which includes six wires with trailers of'everypossible type the wiring system of which may comprise either four or sixwires. The distributing and switching board 34 of the tractor is in thiscase provided with a switch bank 40 with six individual switches 43, 44.48, one for each wire leading to the plug connector of the tractor. Thisplug connector is preferably a dual plug connector 39 such as shown inFigure 6 with two connector members 41, 42, one of said members beingprovided with six pins for connection with the six wire cable on thetrailer and the other being provided with four pins for connection witha four wire cable on the trailer. 'According to the type of trailerwhich is coupled with the tractor either the one or the other half ofthe plug 39 is used.

Each individual switch 43, 44 48 comprises a contact segment 49, acontact arm 50 and six contacts 51 facing the contact segment 49. Bymeans of the movable contact arm the segment 49 may be connected withany one of the six contacts 51. In addition to the six contacts 51 eachof the switches may also have an off contact 67.

Each of the contacts 51 is connected with a wire strand 52, 53, 54 57each leading to one of the pins 58 in the plug member 41. The plugs areindicated by letters a, b, c f. As the segment 49 of each switch 43, 4448 is connected with one of the wire strands, 61, 62 66 of the cable 21it is obviously possible, by adjusting the position of the switches 43,

44 48 by means of the contact arm [ot] to can nect any wire strand 61,62 66 of cable 21 with any one of the wires 52, 53 57 leading to one ofthe pins 58a, b, c f.

If the wiring system of the trailer is a six wire system the driver whencoupling the trailer with a tractor, has merely to adjust the switches43, 44 48 in his distributing and switching box 34 in accordance with aprescribed pattern to establish full control over the trailer lights bymeans of the switching devices of the tractor.

The setting of the switches 43, 44 48 needs much less attention than theindividual connection between each wire of the tractor with the wire ofthe trailer. Practically the number of types of trailers hauled by asingle tractor is limited and therefore a tabulation showing the settingof the switches for each particular trailer type which is in use may beattached to the switch box, indicating clearly the manipulation to bemade when coupling the tractor with a certain type of trailer.

In the second half 42 of the dual connector plug 39 only four pins 59individually indicated at g, h, i, k are arranged, each pin beingconnected with one of the four lines 52, 53, 54, 55. These wires usuallylead to the two directional signals and to the stop light and to thebody lights respectively, and the switches 43, 44 48 must be adjustedaccordingly.

Figure 5 illustrates an example of a tractor with a wiring system havingfour control circuits. Therefore, a connecting cable 21 provided withonly four strands of wire 71, 72, 73, 74 leads to a dual plug indicatedin dotted lines at 70, one part 68 of which carries four pins forconnection with the trailer while the other half 69 carries six pins.The six connections usually comprise an auxiliary conductor used forinner lights or for some caution signal and a further conductor whichleads to ground. The two additional conductors remain unconnected, whenthe trailer is is coupled with a four wire trailer and only the fourremaining wires are used. Switches 75, 76, 77, 78 are again arranged,each of these switches being again provided with a contact segment 79, aset of six contacts and an elf contact 81 and a contact arm, not shown.The adjustment of the switches may be done by means of a handle 80.

The contact segment 79 of each of the switches 75, 76, 77, 78 isconnected with one of the strands 71, 72, 73, 74 of the cable 21 of thetractor. The set of contacts 81 is connected with the wire strands 82,83, 84, 85, 86, 87. The four wires 82-85 may directly be connected withthe connector member 68 adapted for a four wire connection while the twoadditional wires 86, 87 of the six wire connection 69 are joined withthe remaining contacts of the series of six contacts. The switchespermit, as already described, to connect the cable strand with thosesockets wherever they may be located, in the connector, which will makethe right connections with the four cable strands on the trailer whichare to be connected with the four cable strands on the tractor.

As explained before, the switches 75, 76, 77, 78 have to be set by thedriver in accordance with the fixed tabulation directing the setting ofthe switches for the different types of trailers.

The above described system of interchangeable connections simplifies theoperation to a great extent as the personnel which services the tractorand trailer simply couples the tractor with the trailer in the same way,whatever the type of the trailer, and the driver then adjusts theswitches in accordance with the indications of a table, thusestablishing the connections which link the tractor circuit with thecorresponding trailer circuit whatever the location of the socket or pincontacts in the plug to which they have been wired by the manufacturerof the trailer.

It will be understood that unessential changes in the principle of theinvention may be made without in any way departing from the essence ofthe invention as defined by the annexed claims.

Having described the invention what is claimed as new is:

1. An electric coupling system for connecting the wiring systems of atractor and a trailer having corresponding electrical circuitscomprising a fixedly connected connecting plug member of the trailer,said plug member having connector elements connected to the electricalcircuits forming the wiring system of the trailer, a connecting plug ofsaid tractor connected to the electrical circuits of the tractor andadapted to connect individual electrical circuits of the tractor withindividual connector elements of the connecting plug member on thetrailer, and means for shifting the connection of each of the electricalcircuits of the tractor to a selected one of said connector elements.

2. An electric coupling system for connecting the wiring systems of atractor and a trailer having corresponding electrical circuitscomprising a fixedly connected connecting plug member of the trailer,said plug member having connector elements connected to the electricalcircuits forming the wiring system of the trailer, a connecting plug ofsaid tractor connected to the electrical circuits of the tractor andadapted to connect individual electrical circuits of the tractor withindividual connector elements of the connecting plug member on thetrailer, and means for shifting the connection of each of the electricalcircuits of the tractor to a selected one of said connector elements,said means including a switch bank having a plurality of switches equalto the number of said connector elements, each of said switchesincluding a movable element capable of being moved to any of a pluralityof positions, means for making a connection in every position with oneof the electrical circuits of the tractor, and means for making aconnection with each one of the connector elements of the connectingplug member of the tractor.

3. An electric coupling system for connecting the wiring systems of atractor-and a trailer having corresponding electrical circuitscomprising a fixedly connected connecting plug member of the trailer,said plug member having connector elements connected to the electricalcircuits forming the wiring system of the trailer, a connecting plug ofsaid tractor connected to the electrical circuits of the tractor andadapted to connect individual electrical circuits of the tractor withindividual connector elements of the connecting plug member on thetrailer, and means for shifting the connection of each of the electricalcircuits of the tractor to a selected one of said connector elements,said connecting plug member of said tractor being a dual plug memberprovided with two connector means, each of said connector means beingprovided with a ditferent number of connector elements for connectionwith the corresponding connector elements on a selected trailer.

4. An electric coupling system for connecting the wiring systems of atractor and a trailer having corresponding electrical circuitscomprising a fixedly connected connecting plug member of the trailer,said plug member having connector elements connected to the electricalcircuits forming the wiring system of the trailer, a connecting plug ofsaid tractor connected to the electrical circuits of the tractor andadapted to connect individual electrical circuits of the tractor withindividual connector elements of the connecting plug member on thetrailer, and means for shifting the connection of each of the electrical circuits of the tractor to a selected one of said connectorelements, said means including a switch bank having a plurality ofswitches equal to the number of said connector elements, each of saidswitches including a movable element capable of being moved to any of aplurality of positions, means for making a connection in every positionwith one of the electrical circuits of the tractor, and means for makinga connection with each one of the connector elements of the connectingplug member of the tractor, said connecting plug member of said tractorbeing a dual plug member provided with two connector means, each of saidconnector means being provided with a diflerent number of connectorelements for connection with the corresponding connector elements on aselected trailer.

5. A switch bank adapted for use on a tractor to facilitate connectingvarious of the electric lighting-circuits of the tractor to thecorresponding lighting circuits on a trailer drawn by the tractor; saidbank comprising a plurality of selector switches each of which has aplurality of fixed contacts and a movable contact thereon; each movablecontact on a switch being adapted to be moved into contact with each ofthe fixed contacts on said switch to establish an electrical connectiontherewith; means for electrically connecting each of the movablecontacts to one of the lighting circuits of the tractor; and means forelectrically connecting each of the fixed contacts to one of thelighting circuits of the trailer; whereby, when the switches areconnected as set forth, the movable contact of each of the switches maybe moved by the operator into contact with a selected fixed contactthereon to connect each of the lighting circuits of the tractor with thecorresponding lighting circuit of the trailer.

6. A switch bank adapted for use on a tractor to facilitate connectingvarious of the electric lighting circuits of the tractor to thecorresponding lighting circuits on a trailer drawn by the tractor; saidbank comprising a plurality of selector switches, one for each of thelighting circuits of the tractor desired to be connected tocorresponding circuits in the trailer; a set of separate fixed contactsand a single movable contact on each switch, the movable contact on eachswitch being adapted to be moved into contact with each of the fixedcontacts on said switch to establish an electrical connection therewith;means for electrically connecting each of the movable contacts to one ofthe lighting circuits of the tractor; an electric connector secured tothe tractor and having connector elements adapted for electricalconnection with the lighting circuits of the trailer; and electricalconductors connecting the fixed contacts of said switches with theconnector elements in the connector secured to the tractor whereby, whenthe switches are connected as set forth and the connector iselectrically connected to the lighting circuits of a trailer, themovable contact of each of the switches may be moved by an operator intocontact with a selected fixed contact thereon to connect each of thelighting circuits of the tractor with the corresponding lightingcircuits of the trailer.

7. A switch bank adapted for use on a tractor to facilitate connectingvarious of the lighting circuits of the trailer, said last mentionedmeans including a plug connector having a plurality of contacts eachelectrically connected to a fixed contact on said switches; whereby anoperator, by moving the movable contacts of the switches into contactwith selected fixed contacts of the respective switches, canelectrically connect the lighting circuits of the tractor to thecorresponding lighting circuits of the trailer.

8. A switch bank adapted for use on a tractor to facilitate connectingvarious of the electric lighting circuits of the tractor to thecorresponding lighting circuits on a trailer drawn by the tractor; saidbank comprising a plurality of selector switches each of which has aplurality of fixed contacts and a movable contact thereon; each movablecontact on a switch being adapted to be moved into contact with each ofthe fixed contacts on said switch to establish an electrical connectiontherewith; each of said movable contacts being provided with meansadapting it to be electrically connected to one of the lighting circuitsof a trailer; and each of said fixed contacts being provided with meansadapting it to be electrically connected to one of the lighting circuitsof said tractor; whereby, when the switches are connected as set forth,the movable contact of each of the switches may be moved by an operatorinto contact with a selected fixed contact thereon to connect each ofthe lighting circuits of the tractor with the corresponding lightingcircuits of the trailer.

9. In a tractor, an electric coupling device adapted to connect theelectric lighting circuits of said tractor with the correspondingelectric lighting circuits of a trailer provided with a socket memberhaving a plurality of socketed connector elements each of which isconnected to an electric circuit forming part of the lighting system ofthe trailer; said device comprising a connecting plug on said tractorhaving a plurality of jacks adapted to be inserted into the sockets ofthe socket member of the trailer and means comprising a plurality ofmanally operable switches for electrically connecting each of said jacksin any of the electrical circuits forming part of the lighting system ofthe tractor, whereby corresponding electric lighting circuits of thetractor and trailer may be electrically connected by trial operation ofthe switches.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS 1,593,966 Davis July 27, 19252 2,693,539 MadiganNov. 2, 1954-1 74

